A small standing crop of phytoplankton supports a large standing crop of zooplankton. This can be correctly represented by:

Which one of the followings is not a feature of insecticidal protein crystals formed by Bacillus thuringiensis:

Sex chromosomes of female in chicken are:

Match List-l with List-II

List-l (Genes of lac Operon)	List-II (Codes for)
(A) i	(I) \( \beta \)-galactosidase
(B) z	(II) Transacetylase
(C) a	(III) Permease
(D) y	(IV) Repressor

Choose the correct answer from the options given below:

Given below are some statements which should be followed to avoid sexually transmitted infections.
Which of the following are correct?
(A) Avoid sex with unknown partners/multiple partners.
(B) Always use medicated IUDs during coitus.
(C) In case of doubt always consult a qualified doctor and get complete treatment if diagnosed infection.
(D) Adopt natural methods of contraception during coitus.
(E) Use of oral pills before coitus.
Choose the correct answer from the options given below:

The degradation of humus by microbes to release inorganic nutrients is known as-

Read the following passage carefully and answer the given questions.
Insulin consists of two short polypeptide chains- chain A and chain B, that are linked together by disulphide bridges. Some strains of Bacillus thuringiensis produce proteins that kill certain insects such as lepidopterans, coleopterans and dipterans. Bt toxin protein is converted into an active form of toxin due to the alkaline pH of the gut which solubilise the crystals. Transgenic animals that produce useful biological products can be created by the introduction of the portion of DNA (or genes) which codes for a particular product such as human protein (alpha-1-antitrypsin) used to treat emphysema. Plants, bacteria, fungi and animals whose genes have been altered by manipulation are called Genetically Modified Organisms (GMO). GM plants have been useful in many ways. Genetic modification has: (i) made crops more tolerant to abiotic stresses. (ii) reduced reliance on chemical pesticides (pest-resistant crops). (iii) helped to reduce post harvest losses. (iv) increased efficiency of mineral usage by plants (this prevents early exhaustion of fertility of soil). (v) enhanced nutritional value of food.
Transgenic animals that produce useful biological products such as human protein (alpha-1-antitrypsin) used to treat the disorder:

The focal length of the objective of a compound microscope is \( f_o \) and its distance from the eyepiece is L. An object is placed at a distance u from the objective. For proper working of the instrument
(A) L < u
(B) L > u
(C) \( f_o < L < 2f_o \)
(D) L > \( 2f_o \)
Choose the correct answer from the options given below:

Three cells with internal resistance are connected as shown in the figure. The equivalent emf of the combination of three cells is:

Which of the following statements are incorrect with respect to nucleotides ?
(A) Purines and pyrimidines are nitrogenous bases.
(B) Nucleotides and nucleosides are same.
(C) Phosphate group is linked to - OH of 5' C of a nucleoside through phosphoester linkage.
(D) In RNA, every nucleotide residue has an additional - OH group present at 3' position in the ribose.
(E) Thymine is an example of Pyrimidine.
Choose the correct answer from the options given below :

The probability that A speaks the truth is \(\frac{4}{5}\). He throws a die and reports that it is a five. The probability that it is actually a five is:

Arrange the halogens in the increasing order of bond dissociation enthalpy :
(A) \(F_2\)
(B) \(Cl_2\)
(C) \(Br_2\)
(D) \(I_2\)
Choose the correct answer from the options given below :

Thalassemia is: